Can We Measure Correlates of Neuronal Activity with Non-Invasive Optical Methods?
Light in the near-infrared range is only moderately absorbed by water, hemoglobin, and other significant body substances (Wilson, Patterson & Flock, 1987) and therefore penetrates several centimeters inside the head and other body structures. Thus, near-infrared light can be used to study absorption and scattering properties of living tissues. This includes non-invasive, quantitative spectroscopic measurements of the concentration of substances with characteristic absorption spectra in the near-infrared range (such as oxy-and deoxy-hemoglobin) (Chance, 1989). Changes in the scattering properties of the tissue, such as those related to variations in the concentration of glucose, or to other physiological events could also be measured. Near-infrared optical measurements can be taken repeatedly and rapidly, which makes the study of the dynamics of physiological phenomena possible. Since measurements can be taken from circumscribed areas of the brain, it is possible to conduct functional brain imaging studies (see Tamura, this volume).
KeywordsPrimary Visual Cortex Occipital Area Recording Instrument Calcarine Fissure Functional Brain Imaging Study
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- Barbour, R. L., Chang, J., & Graber, H. L., (1994). MR assisted optical tomography. Paper presented at the Meeting on the Integration of Medical Optical Imaging and Spectroscopy and Magnetic Resonance Imaging, Philadelphia, December.Google Scholar
- Chance, B. (Ed.) (1989). Photon migration in tissues. New York: Plenum Press.Google Scholar
- Cohen, L. B. (1972). Changes in neuron structure during action potential propagation and synaptic transmission. Physiological Review, 53, 373–417.Google Scholar
- Frostig, R. D. (1994). What does in-vivo optical imaging tell us about the primary visual cortex in primates? In A. Peters & K. S. Recleaned (Eds.), Cerebral cortex (pp. 331–358). New York: Plenum Press.Google Scholar
- Frostig, R. D., Lieke, E., Ts’o, D. Y, & Grinvald, A. (1990). Cortical functional architecture and local coupling between neuronal activity and the microcirculation revealed by in-vivo high resolution optical imaging of intrinsic signals. Proceedings of the National Academy of Sciences, 87, 6082–6086.ADSCrossRefGoogle Scholar
- Gratton, E., Maier, J. S., Walker, S., Fantini, S., & Franceschini, M. A. (1994). Frequency-domain imaging. Paper presented at the Meeting on the Integration of Medical Optical Imaging and Spectroscopy and Magnetic Resonance Imaging, Philadelphia, December.Google Scholar
- Gratton, E., Mantulin, WW, van de Ven, M. J., Fishkin, J. B., Maris, M. B. & Chance, B. (1990). The possibility of a near-infrared optical imaging system using frequency-domain methods. Proceedings of III International Conference for Peace through Mind/Brain Science, 183-189.Google Scholar
- Hoshi, Y., & Tamura, M. (1993). Dynamic multichannel near-infrared optical imaging of human brain activity. Journal of Applied Physiology, 75, 1842–1846.Google Scholar
- Obrig, H., Kleinschmidt, A., Merboldt, K. D., Dirnagl, U., Frahm, J. & Villringer, A. (1994). Monitoring of cerebral blood oxygenation during human brain activation by simultaneous high-resolution MRI and near-infrared spectroscopy. Proceedings of the Society of Magnetic Resonance, 1, 67 (Abstract).Google Scholar
- Patterson, M. S., & Wilson, B. C. (1991). The propagation of optical radiation in tissue. In M. J. Colles (Ed.), Advances in laser biophysics. England: JAI Press.Google Scholar
- Raichle, M. E. (1994). Visualizing the mind. Scientific American, April, 58-64.Google Scholar
- Regan, D. (1989). Human brain electrophysiology: Evoked potentials and evoked magnetic fields in science and medicine. Amsterdam: Elsevier.Google Scholar
- Tootell, R. B. H., Switkes, E., Silverman, M. S., & Hamilton, S. L. (1988). Functional anatomy of macaque striate cortex: II. Retinotopic organization. Journal of Neuroscience, 8, 1531–1568.Google Scholar
- Villringer, A., & Dirnagl, U. (1995). Coupling of brain activity and cerebral blood flow: Basis of functional neuroimaging. Cerebrovascular Brain Metabolism Review..Google Scholar